Reverse drive control mechanism



3 Sheets-Sheet l G. E. MILLER Filed Aug. '7, 1937 REVERSE- DRIVE CONTROL MECHANISM -Nav. 1.5, 19387.

Nov. 15, 193s. G. E. MILLER 2,136,454 REVERSE DRIVE CONTROL MEGHANISM Fled Aug. "r, 1937 s sheets-sheet 2 Gwowwv.

4Nw. 15, 193s.

G. E. MULLER REVERSE DRIVE CONTRO-L MECHANISM Filed Aug. '7, 1937 3 Sheets-Sheet Patented Nov. 15, 1938 uNrrl-:n' STATES PATENT OFFICE 2,136,454 REVERSE DRIVE 'CONTROL MECHANISM George E. Miller, Findlay, Ohio, assignor to The i Buckeye Traction Ditcher Company, Findlay, Ohio, a corporation of Ohio Application August 7. 1931, semi No. 157,940

s 9 claims.' (Cl. 19a-4) This invention relates primarily to mechanism for controlling the swinging movements of turntables, crane cabs or the like, wherein the driving means is provided with separateclutches selectively engageable to effect a turnlngof the table" in one direction or the other.Y v

The primary object of the invention is the provision in combination witha driving means and a holding means, of simple and eilicient control means therefor operable to normally apply the,

holding means to prevent operation of the connected device and which is automatically released when the driving means is engaged to the driven Figure l is a more or less diagrammatical plan view, with parts broken away, of a swlngingly A, mounted platform and of the drive and control means therefor embodying the invention; Fig. 2 isl a side elevation,` thereof; Fig. 3 is a sectional detail of a clutch used in connection with the` invention; Fig. 4is a side view of the clutch; Fig. 54 is a plan view of a manual control for the differential fluid pressure means used in connection Iwith the invention; Figs. 6 'and rl are sectional '30 views, respectively, on the lines 6--6 and 'I'I in Fig. 5; Fig. 8 is a cross-sectional view on the line 8-8 in Fig. 6, and Fig. 9 is a sectional detail of the valve andiiuid pressure actuated diaphragm means employed to control the brake operation. Referring to the drawings, I designates a platform mounted for swinging movements and which may constitute the mount for a swinging crane. The reversibledrive for the platform, in the 40 present instance, comprises a shait2 mounted thereon and carrying opposed bevel gears 3 and 4 in vmesh with a common driven pinion 5 and each having driven connection with the shaft through respective clutches 6 and 1. The shaft may be connected to any suitable powersource through a driving connection including a gear 8. The f bevel pinion 5 has suitable driving connection with the platform, as well understood in the art. Each' clutch 6, 1, is controlled by differential fluid pressure acting on the diaphragms in respective chambers I0 and II, the diaphragm in each chamber being vacuum actuated to engage the clutch and being movable to permit a release of the clutch when the vacuum action thereon is absent. Each clutch operating diaphragm', one

of which is shown in the chamber I0 and designated I2, is connected to a clutch operating push rod I3, which extends axially into the respective end of the shaft 2 to the associated clutch.

The clutch used in the present instance, a 5 brief description of which may be necessary to understand the operation of the control means, is shown in detail in Figs. 3 and 4. This clutch comprises a loose driven drum member I5; a xed drive member I6, an internal clutch band Il for l0 engagement with the drum' and carried by the member I6, and an operating connection between the control rod I3 and the clutch band I1. This connection includes a bell crank lever 20 fulcrumed to the fixed member I6 and having one 15 arm extending transversely into the shaft in position to be engaged by an end of the rod I3 and rocked by an actuating movement of the rod.

The other arm of the lever 20 engages one arm of a bellv crank lever 2i, which is fulcrumed to the 20 A member I6 at right angles to the lever 20, and has its other. arm connected to the clutch .band by a link 22. The clutch band is connected at one end -to the/member I6, while its other end is freeto permit expansion of the band, except that 25 it is connected to the lever 2l. This leveris normally held in clutch band releasing position lliy a spring 23 acting on a rod attached to the ever.

It is apparent that when the push rod I3 is 30 moved by vacuum action within the associated chamber Illmthe lever 20 is moved in a direction to move the lever 2l against the action of the spring 23 and eiect engagement of the clutch band I1 with the drum I5. and that when the 35 diaphragm is relieved of the vacuum action, the clutch parts, rod I3 and diaphragm I2, will be returned to their normal released positions by the action of the spring 23. It will be understood vthat each clutch member I5 is flxedly connected.,l 40

to the adjacent bevel gear 3 on 4, so that the driving of the clutch drives the gear.

The brake means employed for holding the platform against turning when both clutches are released comprises, in 'the'present instance, a brake shoe 30 acting against the periphery of one l of the clutch members I5 (that of clutch 6 in the present instance) and 'such shoe is connected to and actuated bymovements of a lever 3l.. This 50 4 lever has its long arm connected by a rod 32 to a piston 33 operating in a cylinder 34. Thecylinder at its outer end with respect to the lever 3i is connected to a vacuum source so that vacuum action on the piston 33 moves the lever to apply 65 the brake. A spring It acts to release the brake when vacuum action is absent.

lhe vacuum source includes a tank 4I, wherein vacuum is maintained by a pump 4I, and this tank is normally in open communication with the brake cylinder 34 through a tube 42 in which a normally open control valve 4I is disposed. The tank 4l is in normally closed communication, through a tube 44 to a manual control means 4I and through branch tubes 4l and 41, with the suction side of the respective diaphragm chambers il and Il, through the medium oi' which the clutches 6 and 1 are respectively engaged.

The control 4l in itself is old, being purchased on the market, and is shown (Figs. 5 to 8) and described only suiilciently to enable its operationi'n connection with the present invention to be understood. 'I'his control includes a casing 5I having upper and lower sections divided by a partition member 5I. The lower compartmentl is provided with tour vertically disposed bores 52, l2, I4 and 55 forming valve chambers which are rectangulariy arranged with the chambers 52 and B2 diagonally disposed and each in communication with the vacuum tube 44 from the tank 40 and with the chambers 54 and 55 likewise diagonally disposed and in communication with an air inlettube 56. The partition member Il has an opening therethrough from the top of each of the said valve chambers 52, 53, 54, 55 intoa respective chamber in the upper section oi the control, the interior of said section ior such purpose being centrally divided one way by a vertical partition l1 and centrally the other 'way by a vertical partition. A separate valve l is disposed in each o! said valve chambers and is normally held seated against the partition BI to close the respective -opening therein by an associated spring Il.

A stem 62 projects upward from each valve 60 within the associated compartment of the upper section in position to be acted on byA respective lingers oi' a hand control lever 44. This lever is tulcrumedin the partition 51 crosswise of thepartition I. The lever 84 has four lingers 63, two' at one side of the fulcrum and two at the other side, and positioned to act on the upper ends of the respective valve stems 42.

v open.

.0f me wmmfnconm;lever,susinnsxwitral'posis tion,asshowninlig.6,bothairvalves,whichare disposedintherespectivechambelsandlkare vl'lelili slightly open so that air under atmospheric premirewillbeadmittedthroughtheline Bland .communicating air chambers I4 and'll'to both branch'vacuum tubes thsairvalveonthesameside "l tion oi' the associated clutch.

immaterial as the other branch line with which such air valve is associated should be in communication with the atmosphere. It is thus apparent that when the control lever 64 is in neutral position, both diaphragm chambers l0, Il, are closed to the vacuum tank andopen to the atmosphere, and that a rocking of the lever in either direction will open the vacuum line to one or the other oi the diaphragm chambers and close the air communication therewith, and thus effect an applica- 'I'he automatic control valve 42 in the vacuum v line to the brake cylinder is shown in detail in Fig. 9, and comprises a casing forming a central chamber 10 with longitudinally oiset ports li and 12 for connection with the vacuum line 42,'such chamber also having communication at one end with the atmosphere through ports 13. A valve stem 14 is mounted for reciprocatory movements lengthwise within the chamber 10 and carries two valves 15 ,and 16 which are slidingly mounted on the stem and normally held apart in engagement with respective stops 11 on the stem by an interposed expansion spring 18. The valves 15 and 16 are respectively adapted and normally urged to seat within the casing to close communication respectively between the ports 1l and 13 with the vacuum port 12, which is located on the side o! the valve' with the brake cylinder. `The stem 14, when in its normal position, effected as hereinafter described, stands as shown in Fig. 9, with the air valve 16 seated and the vacuum valve 15 open, so that the vacuum side og the brake cylinder 34 is in communication with the vacuum source. When the stem 14 is moved inward. the

v4vacuum valve 15 iirst moves to close the communication between the vacuum ports 'il and 12, and then continues its movement suiilciently for a right hand stop 11 to engage the air valve 16 and move it to open position to permit admission of atmospheric pressuife to the brake cylinder,

thus relieving the vacuum action therein and per-I mitting release of the brake.

'I'he movement of the valve stem 14 to close the vacuum line and open the air line to the brake cylinder is dependent on the opening oi' either clutch operating vacuum line 46, 41, to the vacuum source. To effect such dependent action, each vacuum branch 46, 41, has communication through a respective branch 46', 41'. with an associated diaphragm chamber 80, the diaphragm Il of which is in connection through a rod 82 with the respective end of a cross-bar 83 pivoted on the valve rod 14. A spring 84 in each diaphragm Achamber 8l acts on the diaphragm therein to normally retain it and the connected rod l2 in its forward position, as shown, with the valve stem 14 held outwardly in open vacuum line position. When either line 4i, 41, is open to the vacuum source through the control 4l, the diaphragm 8l in connection with such line 's subjected to vacuum action and thus caused to move inwardly against the tension of the spring I4 and tetiect a rocking of the cross-bar about its pivotal connection with the other rod 02, and

thus move the valve stem 14 inwardly a sumcient distance to close the vacuum valve 15 andl open the air valve 16 to relieve the brake holding pressure in thebrake cylinder 24. When the vacand open the vacuum line the brake cylinder.

- uum line to the brake cylinder 34 through the valve 43. At the same time. both clutches i and 1 in released position. Ii! it is desired to turn the platform in a direction effected by the application of the clutch 6, the operator throws the control lever 64 in a direction to the left, as shown in Fig. 6, thereby effecting an opening of the valve in the vacuum chamber 52 and a closing of the `assof ciated air Avalve in the air chamber 54. .The line 46 to the diaphragm chamber I0 is thus closed to the atmosphere and open to the vacuum source, thus effecting an engaging operation of the clutch 6. At the same time, the supplemental diaphragm chamber 80 is also open to the vacuum source through the pipes 46, 46', thereby effecting an inward movement of the connected end of the cross-bar 83 and a corresponding movement of the valve rod14 to first close the vacuum valve 15 in the normally open vacuum line 42 to the brake cylinder 34 and then open the air valve 16 to such chamber. It is thus apparent -that the release of the brake and the application of the clutch to turn'the platform i in the desired direction take place at approximately the same time. If the other clutch 1 is to be applied, the control handle B4 is rocked in the opposite direction or to the right, as shown in Fig. 6, thereby releasing the normal opening pressure on the air valve in the chamber 55 to permit its closing and effecting an opening of the vacuum valve in the chamber 53 of the `control 45. This control action closes the branch line 41 to the air and opens it to the vacuum tank, whereby the diaphragm in the chamber Il is actuated to apply clutch 1. At the same time the spring side of the supplemental diaphragm chamber 8B in communication with the vacuum line 41, 41', is open to the vacuum source, thereby actuating the diaphragm and communicating movement to the valve rod 14 to close the brake cylinder communication with the vacuum tank and open it to the atmosphere topermt a release ofthe brake.

It is apparent that while the present control is applied to the reversible driving means for a crane `cab platform or other swinging member where two clutches are employed to effect movement in i one or the other direction, it may be used in vother connections.

I wish it understood thatmy invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous modifications and changes without de-u parting from the spirit of the claims.

` Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent, is:

1. In combination, a driven member capable oi 1 movements in opposite directions, means including a clutch for driving said memberin one direction, a brake for preventing member driving action of said means, controlled differential fluid pressure means operable toapply said clutch, dif'- ferential fluid pressure means `normally acting to -apply said brake, and fluid pressure controlled .means automatically Aoperable to render said brake applying means inoperative when the clutch applying means is rendered operative.

l 2. In combination, a driven member capable of f" 76 movements in' opposite directions, means includline, a valve normally closing said line, and valve cally operable to release said releasable'means Y when said first fluid pressure means is operated to apply the clutch and including a fluid pressure 10 opening means controlled by said first uid pressure means.

3. In combination, a driven member capable of movements in opposite directions, means for driv- Y ing said member including a clutch and a brake, 15 l and differential fluid pressure means including a manual control valve and an automatic valve,` said last means acting to normally retain said brake applied and Voperable upon'predetermined movement of said control valve to effect engage- 20 ment of the clutch and to actuate said automatic valve to release the brake. l

4. In combination, a member capable of movements in opposite directions, means for driving said member including a clutch and a brake, separate differential iiuid pressure actuated means' for applying said clutch and brake, means rforming -connections between a differential fluid pressure source and both said separate means, a normally open supplemental valve in said brake communication, a manual control means operable to open said clutch communication to said source to eect engagement of the clutch, and means in connection with said supplemental valve and automatically operable by differential fluid pressure when said clutch communication is open to eect closing of said brake communication.

5. In combination, a driven member capable of movements in opposite directions, means includ ing a clutch for driving said member in one direc- 46 tion, a brake for preventing movement of the member, separate means actuated by differential fluid pressure to apply said clutch and brake. a vacuum source, means forming communication between said source and each of said separate means and having a branch portion. a normally open valve in said brake communication, a manual control normally closing said clutch commu- .nication and operable to open the same and also 6. In combination, a driven member capable of movements in opposite directions, drive means for said member including separate forward and reverse clutches, a brake operable to prevent move- Y mentof the member, separate differential fluid pressure actuated means associated with each co clutch and with the brake to selectively apply them, a differential iiuid pressure sourcemeans providing separate communication between said L source and each oi said separate means, a normally open supplemental valve in said brake coma5 munication, a main valve manuallyoperable to selectively open and close said clutch communications, and means including separate units connected to said supplementalvalve and disposed in respective portions of said clutch communications y0 and operable by differential fluid pressure to close said supplemental valve when either of said clutch communications is open.

7. In combination, a driven member capable of movements in opposite directions, means for drivlo ing said member including two reverse driving clutches, a brake operable to prevent movements of said member, separate vacuum actuated means `for applying each of said clutches and said brake, a vacuum source, means forming communication between said source and each of said clutch and brake applying means and each -clutch communication having a branch. a normally open valve in said brake communication, a separate vacuum actuated means in each oi' said branches and vacuum actuated toI close said valve when either branch is open to said source, and means for closing the communication between said source and each of said clutch communications and its branch and manually operable to selectively open said communications.

8. In combination, a driven member capable of movements in opposite directions, means for driving said member in one direction and including a clutch, brake means operable to resist movement of said member, separate vacuum actuated means for applying said clutch and brake, a vacuum source, means providing separate communication between said source and each of said applying means, a normally open valve in said brake communication, means operable by vacuum action in said clutch communication to actuate said valve to close the brake communication, andmain control means for closing said clutch communication and operable to open the same.

9. InI combination, a driven member capable of movements in opposite directions, mechanism for driving said member in opposite directions including a' plurality of clutches, a brake for said mechanism operable to hold the member in any driven position, a vacuum source, separate vacuum actuated means for each clutch and for the brake to apply the same, said clutches and brake standing released whennot being applied by the vacuum means, means forming separate communication between said source and each of said clutches and said brake applying means, the brake communication being normally open, means automatically operable to close said brake communication when the vacuum action is present Ain any of said clutch communications, and mea'ns closing each of said clutch communications and manually operable to selectively open the same.

GEORGE E. MILLER. 

